Panicum philadelphicum |
Panicum capillarioides |
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panic de philadelphie, Philadelphia panic grass, Philadelphia witchgrass |
long-beak witchgrass, slender panicgrass |
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Habit | Plants annual; hirsute, hairs papillose-based, usually yellow-green to green, sometimes purplish. | Plants perennial; cespitose from a knotty crown, hirsute, hairs papillose-based or glabrous. | ||||||||
Culms | 8-100 cm tall, about 1 mm thick, erect to decumbent, simple to profusely branched; nodes sparsely to densely pilose. |
30-75 cm tall, 1-2 mm thick, terete to slightly compressed, erect or ascending, stiff, often bent at the nodes, simple or sparingly branched; nodes densely pubescent. |
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Sheaths | shorter than or equaling the internodes, rounded, hirsute, green or tinged with purple, margins ciliate; ligules 0.5-1 mm; blades 12-30 cm long, 2-12 mm wide, stiffly erect or ascending, flat, pubescent, sometimes sparsely so, hairs papillose-based, bases truncate, apices attenuate. |
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Leaves | often crowded basally; sheaths rounded, usually longer than the internodes, hispid, hairs papillose-based, to 5 mm; ligules 0.5-1.5 mm; blades 3-30 cm long, 2-12 mm wide, linear, ascending to erect, flat, hirsute to sparsely pilose, greenish or purplish, bases truncate to subcordate and ciliate on the margins, apices acute. |
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Panicles | 7-27 cm long, 4-24 cm wide, 1/4 - 1/3 as long as the plants, diffuse, usually exserted at anthesis, not breaking at the base of the peduncles to become a tumbleweed; rachises glabrous or sparsely pilose basally; primary branches spreading, secondary branches and pedicels confined to the distal 2/3 secondary branches diverging to appressed, with 1-4 spikelets; pedicels 3-15 mm, spreading to appressed, scabrous or hirsute; pulvini glabrous or pilose. |
terminal, 15-30 cm long, 10-12(26) cm wide, usually shortly exserted, scarcely overtopping the blades; rachises hispid, sometimes glabrous basally; primary branches alternate or opposite, divergent, secondary branches divergent, most abundant on the distal 1/3 of the primary branches, with 1-3 spikelets; pedicels 2-20 mm, confined to the distal 1/3 of the branches; pulvini poorly developed, shortly pilose. |
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Spikelets | 1.4-2.4 mm long, 0.5-0.7 mm wide, usually green, glabrous. |
5-6.5 mm long, 1-1.2 mm wide, glabrous, long-acuminate. |
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Lower glumes | 0.5-0.9 mm, usually less than 1/2 as long as the spikelets, 3-4-veined, truncate to acuminate; upper glumes 1.6-2 mm, 7-veined, veins not prominent; lower lemmas 1.6-1.9 mm, 7-9-veined, veins not prominent; lower paleas absent; lower florets sterile; upper florets 1.5-1.7 mm long, about 0.4 mm wide, often dark brown, sometimes disarticulating, apices minutely papillose. |
2-3 mm, about 1/2 as long as the spikelets, attached about 0.4 mm below the upper glumes, 5-7-veined, acute to obtuse; upper glumes and lower lemmas 5-6 mm, exceeding the upper florets by 3-4 mm, 9-13-veined; lower florets sterile; lower paleas 1.5-2 mm, acute; upper florets 1.6-2 mm long, 1-1.1 mm wide, smooth, chestnut brown when mature. |
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2n | = 18. |
= 36. |
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Panicum philadelphicum |
Panicum capillarioides |
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Distribution |
AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
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TX |
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Discussion | Panicum philadelphicum grows in open areas such as fallow fields, roadside ditches, receding shores, and rock crevices. It is restricted to the eastern part of the Flora region. It intergrades with P. capillare, possibly as a result of hybridization, especially in the southeastern United States. Seeds germinating on receding shores in late summer often produce tiny plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Panicum capillarioides grows in sandy grasslands, oak savannahs, and rangelands from southern Texas to northern Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 459. | FNA vol. 25, p. 464. | ||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | P. tuckermanii | |||||||||
Name authority | Bernh. ex Trin. | Vasey | ||||||||
Web links |